Savvy supermarket shopper: The price of tinned tomatoes differs hugely,
but does the quality follow suit?

Anyone who has ever turned their nose up at the supermarket economy ranges should take a shopping trip with Jack Monroe. The dynamic, pint-size 24-year-old female journalist and blogger (agirlcalledjack.com) took me on a tour of her local Sainsbury's, showing me how she managed to cook for herself and her toddler son on less than £10 a week.

We whistled around at top speed – no time for impulse-buying under Jack-the-Ladette's auspices. Bags of mixed veg and low-cost bread went into the basket, along with cheapo brie and bacon scraps. At the canned vegetable aisle she deftly swooped down and snatched a tin of tomatoes in the austere orange-and-white livery of the Basics range. "Look at the low shelves," she advised. "That's where the cheapest stuff goes." Was she never tempted to trade up to something a little … better? Jack fixed me with a hawk-like eye. "They are tomatoes. In a tin." Quite.

No question, with prices ranging from 31p for economy tomatoes to £1.39 and above for the same-sized 400g tin of premium tomatoes, the potential saving is enormous. Especially as tinned tomatoes are one of most people's store-cupboard staples, chucked into everything from a pasta sauce to a casserole.

But it did get me thinking. Economy-brand tomatoes are carefully price-matched by the major supermarkets. But are all equal?

Not if you read the label, they aren't. Now, nutrition data is generally determined by a lab test and it's impossible to be completely consistent. Tomatoes, peas, mandarins, whatever, are not grown in a lab and vary through the year and even from plant to plant. Even so, the variation was surprising.

All the economy brands reckoned that they were 60pc tomato (the rest being juice and a tiny bit of citric acid) apart from Waitrose at 65pc – comparable to premium tinned tomatoes, but then at that price so they should be.

Sugar levels were as high as 15.2g per tin for Sainsbury's plum tomatoes, more than 50pc higher than 10g for both Asda plum and chopped tomatoes. Protein content per can ran from 2.4g for Morrisons to 4.8g for both Asda and Waitrose. With recommended minimums for an adult male at around 55g, it's hardly revolutionary but then (as someone said) every little helps.

Time for a proper taste test. I rounded up both chopped and plum tomatoes from Sainsbury's, Tesco, Asda, Morrisons, Lidl and Waitrose, throwing in a couple of the high-end tins as benchmark.

For the test, I drained the tomatoes through a sieve to separate the liquid from the solids, to best assess the quality of the tomatoes themselves, and the all-important juices. Then came the tasting. I was looking for rich-tasting tomatoes, ideally with good thick juices, as that would make for less boiling down to make a nice sauce. Bitterness and metallic tastes were marked down, as they would only be magnified in cooking.

So here are the results..

Lidl (31p)The plum tomatoes had notably thick juices without bitterness and a natural sweet, herby quality. Enough solid tomato to half fill the tin, even after draining off the juice. Outstanding overall, preferable to many of the more expensive and even premium brands. The winner 9/10

Chopped Thinner juices than the plum and less richly flavoured. 5/10

Sainsbury's Basics (31p) The plum tomatoes had a good half-tin full of tomatoes after draining. Juices are thin and a bit metallic-tasting. Tomatoes almost flavourless. 3/10

Chopped Uniquely, these come in a handy Tetra Pak. As for the contents, they had thin juices, but a more mellow flavour than the plum. 4/10

Morrisons Saver (31p) The plum tomatoes had a huge piece of skin on one tomato. Mild juices, and sharp-tasting fruit. 5/10

Chopped Mild and very average. 5/10

Waitrose Essential (55p)Thick juices with a good tomatoey flavour, but a little tinny bitterness. Less than half full of "flesh" but those juices are thick. Great stuff but at 55p a tin, hardly fair to compare to the economy at 31p. 9/10

Chopped Thinner juices and less rich flavour. 6/10

Tesco (31p)Bland, like the Sainsbury's one, though there seems to be more tomato in the can. Juices a tad thicker, but a tinny flavour. 4/10

Chopped Fairly thick juices (good) but a lot of bits of skin, and a thin, sharp flavour (bad). 6/10